The invention concerns a novel process for the synthesis of N-[(1'-allyl-2'-pyrrolidinyl) methyl]2-methoxy-4,5-azimidobenzamide of the following formula: ##STR1## That compound and its preparation are described in U.S. Pat. No. 4,039,672, issued Aug. 2, 1977. The compound is useful as a medicament and in particular, has therapeutic benefits in the gastro-enterological field.
The presence of an amide function in the molecule has permitted a conventional synthesis by the condensation of 2-methoxy-4,5-azimidobenzoic acid and N-allyl-2-aminomethyl pyrrolidine, as precursors, either directly or by way of a reactive derivative of 2-methoxy-4,5-azimidobenzoic acid or N-allyl-2-aminomethyl pyrrolidine. For example, 2-methoxy-4,5-azimidobenzoic acid has been reacted with products obtained (1) by the preliminary reaction of the precursor amine with phosphorus chlorides, phosphorus oxychloride or substituted chlorophosphites, or (2) by the preliminary reaction of an isocyanate with the precursor amine Further, esters (alkyl or cyanomethyl or methoxymethyl esters) or amides, azides, mixed or symmetrical acid anhydrides, and other derivatives of 2-methoxy 4,5-azimidobenzoic acid can be reacted with N-allyl 2-aminomethyl pyrrolidine to form the Title compound
Such conventional processes all require the use of starting materials which are not generally commercially available. The difficulty in obtaining such reactants is a drawback to the synthesis of the Title compound.